To produce rolled sushi mechanically, there has been proposed a cooked rice molding apparatus as disclosed in Japanese Patent Application Publication No. 2002-45129. In this cooked rice molding apparatus, after rice seasoned with vinegar (hereinafter, referred to as sushi rice) supplied from a hopper has been spread over a dried laver sheet placed on a rolling-up bamboo plate while being rolled into a plate shape by a rolling section, the sushi rice is rolled by the dried laver sheet into a rod shape by deforming the rolling-up bamboo plate into a cylindrical shape.
In Japanese Patent Application Publication No. 2002-45129, the rolling-up bamboo plate includes four plate members, and these plate members are connected to each other rotatably. Thereby, the rolling-up bamboo plate is deformed into a cylindrical shape by bringing both ends of the plate members close to each other from the state in which the plate members are developed horizontally.
The rolled sushi is of several kinds, and one of them is rolled sushi called “back rolled sushi”. The back rolled sushi is generally rolled sushi that is rolled so that sushi rice is directed to the outside with respect to a dried laver sheet, and is especially popular as a California roll in foreign countries because the dried laver sheet does not come out to the surface. Incidentally, there is available a method in which back rolled sushi is made without the use of dried laver sheet.
Thereupon, in producing the back rolled sushi by using the aforementioned cooked rice molding apparatus, the process is merely such that, first, sushi rice is spread over the rolling-up bamboo plate, then a dried laver sheet being placed on the sushi rice, and thereafter the sushi rice is rolled together with ingredients by the rolling-up bamboo plate.
Unfortunately, when back rolled sushi is made by the conventional cooked rice molding apparatus, there arises a problem as described below. The conventional rolling-up bamboo plate has been composed of four plate members having almost the same width, and a cylindrical space for rolling up sushi rice therein has been formed by bringing both ends of the plate members close to each other.
Therefore, when sushi rice is spread over the conventional rolling-up bamboo plate, a dried laver sheet is placed on the sushi rice, and ingredients are placed on the dried laver sheet, whereby rolling is performed, a force for fixing grains of sushi rice to each other is weak because the sushi rice is arranged on the outside of the dried laver sheet, so that the back rolled sushi is disintegrated easily merely by being held by hand.
Also, since the dried laver sheet is arranged so as to wrap the ingredients, the ingredients are easy to move, and therefore the ingredients sometimes move at the moment when the back rolled sushi is shaped. Therefore, to make back rolled sushi so as not to disintegrate, it is necessary to roll sushi rice in a spiral form together with a dried laver sheet.
The present invention has been made to solve the above problems, and accordingly an object thereof is to provide a cooked rice molding apparatus capable of efficiently making back rolled sushi in which sushi rice is arranged so as to be directed to the surface side.